Vesicles (or liposomes) are self-assembled “nano-containers” formed by lipids or surfactants in aqueous solution.1 These structures are ˜100 nm in size and comprise an aqueous core and a lipid bilayer. The aqueous core can be used to encapsulate hydrophilic molecules such as drugs, proteins, or genes, while hydrophobic and amphiphilic substances can be integrated into vesicle bilayers.1 Few, if any, other nanostructures demonstrate this level of versatility as carriers of useful payloads. Accordingly, vesicles have been explored and exploited for a myriad of applications, including targeted drug delivery, gene transfection, imaging agents, biosensors, food science, and cosmetics.2 
Recently, there has been considerable interest into the capture of intact vesicles at precise locations on solid substrates.3-14 The motivation for such studies includes: (a) fundamental aspects, e.g., related to vesicles as biological models for adherent cells; as well as (b) applied aspects related to the fabrication of biosensors or modified biomaterials. For example, the internal volume of intact vesicles would be available for entrapping biomolecules, drugs, or fluorescent molecules, which could be useful for sensor and immunoassay applications. In addition, proteins embedded in vesicle bilayers are expected to more closely mimic their in vivo function compared to the same proteins in supported planar bilayers.4,12 There is particular interest in creating “vesicle arrays” via the spatially controlled immobilization of vesicles, which could spawn a new generation of biomolecular assay tools.4,9 
Previous attempts to capture intact vesicles with spatial precision have employed DNA tethering, 4-6 covalent binding to gold or polystyrene,7,8 or biotin-streptavidin linking schemes.10-12 These methods generally involve labor-intensive experimental procedures or expensive chemical labels. An alternate simpler approach is to use amphiphilic polymers bearing hydrophobic (lipophilic) moieties as tethers to bind either supported lipid bilayers or vesicles to surfaces.13-18 This approach has been used to capture label-free vesicles on the commercially available Biacore L1 chip;13,14 however, this approach does not offer significant spatial resolution. A greater level of spatial and temporal control over vesicle capture (i.e., onto specific areas of a given surface at a given time) could be advantageous for many applications, including for the creation of vesicle arrays.